The present invention relates to a job scheduling analysis method in a computer system in which a plurality of jobs can operate in parallel, and more particularly to a job scheduling analysis method in which jobs are virtually executed supposing the transfer to a computer system which has a structural difference in job multiplicity, CPU performance, the number of CPUs or the like.
JP-A-5-67069, JP-A-6-83646 and JP-A-6-149597 have disclosed job scheduling, job simulation and job multiplicity control.
In the conventional on-line processing in a large-scale banking system or the conventional on-line processing for merchandise management in a physical distribution industry, a large number of works are performed in order to improve customer's services. The on-line processing is accompanied with a batch data processing for totalling data handled in those works. With the increase of the amount of data to be processed in the on-line processing and the variation of the kind of on-line services, there is a tendency that the amount of data to be processed in the batch processing is increased and the contents of batch processing are complicated.
In general, jobs for performing the on-line processing are called on-line jobs and jobs for performing the batch processing are called batch jobs. In order to cope with the increased number of works, there is a tendency to structure a computer system having a plurality of CPUs so that a batch work is performed by the system.
One technique for structuring such a computer system with plural CPUs includes a system in which a plurality of CPUs are operated by one operating system (OS) with one main memory held in common. This system is called a tightly-coupled multiprocessor system.
Another structuring technique includes a system in which a plurality of computers each having an independent CPU and main storage are coupled by a channel-to-channel coupling device. This system is called a loosely-coupled multiprocessor system.
In the computer system based on each of the structuring techniques mentioned above, it is necessary to organize an efficient job schedule so that a batch processing is completed in a short time. Especially in the loosely-coupled multiprocessor system in which a plurality of independent OSes operate, it is necessary to perform a work with the OSes cooperate.
In recent years, the batch processing is complicated with the variation of works and the increase of the amount of data, as mentioned above. For the purpose of shortening a job processing time, there can be considered a method in which the CPU performance of a computer is improved or a method in which the multiplicity of jobs is increased. But, the improvement of single CPU performance in the former method is nearing a limit in the present situation of the art. Therefore, it seems that the increase of job multiplicity in the latter method is sure to become indispensable for years to come.
However, in order to realize the increase of a batch job multiplicity without destroying the correlation of complicated batch jobs, it is required that the efficiency of job scheduling should be improved. Otherwise, it is not possible to make efficient use of the computer resource of the multiprocessor system.